Biofeedback-assisted heart rate modification after myocardial infarction

Four patients who had suffered a myocardial infarction were given biofeedback training in order to assess (1) the possibility of increasing heart rate variability with the help of a feedback; (2) the possible cardiac consequences, from the clinical viewpoint, of biofeedback treatment. A biofeedback procedure alternately increasing and decreasing heart rate under instruction and feedback-plus-instruction conditions, was used. Evaluation of clinical parameters was effected by Holter dynamic ECG and by means of a graded submaximal effort test on the cycloergometer. The results show: (1) poor capacity to increase heart rate variability, but a tendency towards small unidirectional modifications; (2) no significant clinical modification except in isolated parameters. Further study is necessary to assess the usefulness of biofeedback training in the rehabilitation treatment of post-infarction patients. The datum, confirmed elsewhere, concerning apparent cardiovascular "rigidity' in such patients, is interesting but requires clarification.